/**
 * Copyright 2010-2012 initialize4j.org
 *
 * <pre>
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 * </pre>
 */
package org.initialize4j.service.modify;

import java.lang.reflect.Field;

import org.apache.commons.beanutils.ConvertUtils;

/**
 * {@link Modifier} implementation used for modifying a Java bean's
 * field value with a given String value and automatic conversion.
 *
 * @author <a href="hillger.t@gmail.com">hillger.t</a>
 */
class ConverterModifier implements Modifier {
  private final String value;

  ConverterModifier(String value) {
    this.value = value;
  }

  /**
   * {@inheritDoc}
   */
  @Override
	public void change(Object bean, String fieldName) {
    try {
    	Class<?> fieldType = extractTypeOfBeanNamedField(bean, fieldName);
      Object changed = ConvertUtils.convert(this.value, fieldType);

      modifyFieldWithChangedValue(bean, fieldName, changed);
    }
    catch (Exception e) {
      throw new RuntimeException(e);
    }
  }

	private Class<?> extractTypeOfBeanNamedField(Object bean, String fieldName) throws Exception {
		return bean.getClass().getDeclaredField(fieldName).getType();
  }

	private void modifyFieldWithChangedValue(Object bean, String fieldName, Object convertedValue) throws Exception {
		Field field = bean.getClass().getDeclaredField(fieldName);
		boolean accessible = field.isAccessible();
		field.setAccessible(true);
		field.set(bean, convertedValue);
		field.setAccessible(accessible);
	}
}
